Estuaries





By: Royce and Amber

Basic Info:

Estuaries are wetlands where a river meets the sea, and the salt water is greatly diluted by the freshwater.

An estuary is a rich ecosystem full of life, and growth. Due to the meeting of salt water and fresh water creating a rich soil known as silt, plants are able to grow rapidly and spread out throughout the estuary. Animals, fish, and minerals are brought in and out by the flow of the river and the tide of the ocean. In an estuary there are multiple species of phytoplankton, and larger zoo plankton, as well as algae and bacteria. Since there are so many plants and they grow so rapidly, the soil is rich with dead leaves that is broken down into detritus or dead matter.

It is also typically home to young fish prior to their maturing and travel into the depths of the ocean. Many species of crab, worms, and snails live in the mud at the bottom of the estuary and feed on dead matter, and leave the sand and silt as waste, recycling the fertile silt to be used again in the soil. Birds and fish feed on these smaller creatures in the estuary since there is an abundance of them. There are over 30 different types of filter feeding organisms that live in the plant roots and survive by filter feeding, which the larger fish also use as food. Estuaries are home to fewer species than other aquatic ecosystems. They typically serve as nursery and spawning grounds for fish and shellfish. Waterfowl use the grounds as resting stops during migrations.

Types of Estuaries:


Salt marshes are categorized by the salt-tolerant grasses above the low-tide line and by sea grasses underwater. They form a temperate zone. They can be found on the east coast of North America from southern Maine to Georgia. The Chesapeake Bay estuary in Maryland is one of the largest systems of connected salt marshes.


external image satellite-chesapeake.jpg

Mangrove swamps are coastal wetlands that are widespread across tropical regions, including southern Florida and Hawaii. There are multiple species of salt-tolerant trees called mangroves. See grasses are also common in these swamps. They are valuable nurseries to fish and shellfish. Florida's Everglades National Park is the largest mangrove area in the United States.

external image jim-wark-aerial-view-of-wetlands-everglades-national-park-usa.jpg







Works Cited:

http://www.britannica.com/EBchecked/topic/75627/boundary-ecosystem/70746/Boundary-systems-between-waters#ref=ref588706
http://www.teara.govt.nz/en/estuaries/2